| 1. |
- Demmelmaier, Ingrid, 1960-, et al.
(författare)
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Does exercise intensity matter for fatigue during (neo-)adjuvant cancer treatment? The Phys-Can randomized clinical trial
- 2021
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Ingår i: Scandinavian Journal of Medicine and Science in Sports. - : Wiley. - 0905-7188 .- 1600-0838. ; 31:5, s. 1144-1159
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Tidskriftsartikel (refereegranskat)abstract
- Exercise during cancer treatment improves cancer-related fatigue (CRF), but the importance of exercise intensity for CRF is unclear. We compared the effects of high- vs low-to-moderate-intensity exercise with or without additional behavior change support (BCS) on CRF in patients undergoing (neo-)adjuvant cancer treatment. This was a multicenter, 2x2 factorial design randomized controlled trial (Clinical Trials NCT02473003) in Sweden. Participants recently diagnosed with breast (n = 457), prostate (n = 97) or colorectal (n = 23) cancer undergoing (neo-)adjuvant treatment were randomized to high intensity (n = 144), low-to-moderate intensity (n = 144), high intensity with BCS (n = 144) or low-to-moderate intensity with BCS (n = 145). The 6-month exercise intervention included supervised resistance training and home-based endurance training. CRF was assessed by Multidimensional Fatigue Inventory (MFI, five subscales score range 4-20), and Functional Assessment of Chronic Illness Therapy-Fatigue scale (FACIT-F, score range 0-52). Multiple linear regression for main factorial effects was performed according to intention-to-treat, with post-intervention CRF as primary endpoint. Overall, 577 participants (mean age 58.7 years) were randomized. Participants randomized to high- vs low-to-moderate-intensity exercise had lower physical fatigue (MFI Physical Fatigue subscale; mean difference −1.05 [95% CI: −1.85, −0.25]), but the difference was not clinically important (ie <2). We found no differences in other CRF dimensions and no effect of additional BCS. There were few minor adverse events. For CRF, patients undergoing (neo-)adjuvant treatment for breast, prostate or colorectal cancer can safely exercise at high- or low-to-moderate intensity, according to their own preferences. Additional BCS does not provide extra benefit for CRF in supervised, well-controlled exercise interventions.
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| 2. |
- Gad, Helge, et al.
(författare)
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MTH1 inhibition eradicates cancer by preventing sanitation of the dNTP pool
- 2014
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Ingår i: Nature. - : Nature Publishing Group. - 0028-0836 .- 1476-4687. ; 508:7495, s. 215-221
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Tidskriftsartikel (refereegranskat)abstract
- Cancers have dysfunctional redox regulation resulting in reactive oxygen species production, damaging both DNA and free dNTPs. The MTH1 protein sanitizes oxidized dNTP pools to prevent incorporation of damaged bases during DNA replication. Although MTH1 is non-essential in normal cells, we show that cancer cells require MTH1 activity to avoid incorporation of oxidized dNTPs, resulting in DNA damage and cell death. We validate MTH1 as an anticancer target in vivo and describe small molecules TH287 and TH588 as first-in-class nudix hydrolase family inhibitors that potently and selectively engage and inhibit the MTH1 protein in cells. Protein co-crystal structures demonstrate that the inhibitors bindin the active site of MTH1. The inhibitors cause incorporation of oxidized dNTPs in cancer cells, leading to DNA damage, cytotoxicity and therapeutic responses in patient-derived mouse xenografts. This study exemplifies the non-oncogene addiction concept for anticancer treatment and validates MTH1 as being cancer phenotypic lethal.
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| 3. |
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| 4. |
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| 5. |
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| 6. |
- Andersson, Ronnie, 1975, et al.
(författare)
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EP2819891 B1
- 2016
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Patent (övrigt vetenskapligt/konstnärligt)
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| 7. |
- Berntsen, Sveinung, et al.
(författare)
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Design of a randomized controlled trial of physical training and cancer (Phys-Can) - the impact of exercise intensity on cancer related fatigue, quality of life and disease outcome
- 2017
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Ingår i: BMC Cancer. - : Springer Science and Business Media LLC. - 1471-2407. ; 17:1, s. 1-12
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Tidskriftsartikel (refereegranskat)abstract
- Background: Cancer-related fatigue is a common problem in persons with cancer, influencing health-related quality of life and causing a considerable challenge to society. Current evidence supports the beneficial effects of physical exercise in reducing fatigue, but the results across studies are not consistent, especially in terms of exercise intensity. It is also unclear whether use of behaviour change techniques can further increase exercise adherence and maintain physical activity behaviour. This study will investigate whether exercise intensity affects fatigue and health related quality of life in persons undergoing adjuvant cancer treatment. In addition, to examine effects of exercise intensity on mood disturbance, adherence to oncological treatment, adverse effects from treatment, activities of daily living after treatment completion and return to work, and behaviour change techniques effect on exercise adherence. We will also investigate whether exercise intensity influences inflammatory markers and cytokines, and whether gene expressions following training serve as mediators for the effects of exercise on fatigue and health related quality of life. Methods/design: Six hundred newly diagnosed persons with breast, colorectal or prostate cancer undergoing adjuvant therapy will be randomized in a 2 × 2 factorial design to following conditions; A) individually tailored low-to-moderate intensity exercise with or without behaviour change techniques or B) individually tailored high intensity exercise with or without behaviour change techniques. The training consists of both resistance and endurance exercise sessions under the guidance of trained coaches. The primary outcomes, fatigue and health related quality of life, are measured by self-reports. Secondary outcomes include fitness, mood disturbance, adherence to the cancer treatment, adverse effects, return to activities of daily living after completed treatment, return to work as well as inflammatory markers, cytokines and gene expression. Discussion: The study will contribute to our understanding of the value of exercise and exercise intensity in reducing fatigue and improving health related quality of life and, potentially, clinical outcomes. The value of behaviour change techniques in terms of adherence to and maintenance of physical exercise behaviour in persons with cancer will be evaluated. Trial registration:NCT02473003 , October, 2014.
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| 8. |
- Boström, Henrik, et al.
(författare)
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On Evidential Combination Rules for Ensemble Classifiers
- 2008
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Ingår i: Proceedings of the 11th International Conference on Information Fusion. - : IEEE. - 9783800730926 - 9783000248832 ; , s. 553-560
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Konferensbidrag (refereegranskat)abstract
- Ensemble classifiers are known to generally perform better than each individual classifier of which they consist. One approach to classifier fusion is to apply Shafer’s theory of evidence. While most approaches have adopted Dempster’s rule of combination, a multitude of combination rules have been proposed. A number of combination rules as well as two voting rules are compared when used in conjunction with a specific kind of ensemble classifier, known as random forests, w.r.t. accuracy, area under ROC curve and Brier score on 27 datasets. The empirical evaluation shows that the choice of combination rule can have a significant impact on the performance for a single dataset, but in general the evidential combination rules do not perform better than the voting rules for this particular ensemble design. Furthermore, among the evidential rules, the associative ones appear to have better performance than the non-associative.
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| 9. |
- Boström, Henrik, et al.
(författare)
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On the Definition of Information Fusion as a Field of Research
- 2007
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- A more precise definition of the field of information fusion can be of benefit to researchers within the field, who may use uch a definition when motivating their own work and evaluating the contribution of others. Moreover, it can enable researchers and practitioners outside the field to more easily relate their own work to the field and more easily understand the scope of the techniques and methods developed in the field. Previous definitions of information fusion are reviewed from that perspective, including definitions of data and sensor fusion, and their appropriateness as definitions for the entire research field are discussed. Based on strengths and weaknesses of existing definitions, a novel definition is proposed, which is argued to effectively fulfill the requirements that can be put on a definition of information fusion as a field of research.
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| 10. |
- Brax, Christoffer, et al.
(författare)
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Evaluating Precise and Imprecise State-Based Anomaly Detectors for Maritime Surveillance
- 2010
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Ingår i: Proceedings of the 13th International Conference on Information Fusion. - : IEEE. - 9780982443811 ; , s. Article number 5711997-
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Konferensbidrag (refereegranskat)abstract
- We extend the State-Based Anomaly Detection approach by introducing precise and imprecise anomaly detectors using the Bayesian and credal combination operators, where evidences over time are combined into a joint evidence. We use imprecision in order to represent the sensitivity of the classification regarding an object being normal or anomalous. We evaluate the detectors on a real-world maritime dataset containing recorded AIS data and show that the anomaly detectors outperform previously proposed detectors based on Gaussian mixture models and kernel density estimators. We also show that our introduced anomaly detectors perform slightly better than the State-Based Anomaly Detection approach with a sliding window.
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| 11. |
- Ericson, Stefan, et al.
(författare)
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Information Fusion for Autonomous Robotic Weeding
- 2009
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Ingår i: INFORMATIK 2009. - : Köllen Druck + Verlag GmbH. - 9783885792482 ; , s. 2461-2473
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Konferensbidrag (refereegranskat)abstract
- Information fusion has a potential applicability to a multitude of differentapplications. Still, the JDL model is mostly used to describe defense applications.This paper describes the information fusion process for a robot removing weed ina field. We analyze the robotic system by relating it to the JDL model functions.The civilian application we consider here has some properties which differ from thetypical defense applications: (1) indifferent environment and (2) a predictable andstructured process to achieve its objectives. As a consequence, situation estimatestend to deal with internal properties of the robot and its mission progress (throughmission state transition) rather than external entities and their relations. Nevertheless, the JDL model appears useful for describing the fusion activities of the weeding robot system. We provide an example of how state transitions may be detected and exploited using information fusion and report on some initial results. An additional finding is that process refinement for this type of application can be expressed in terms of a finite state machine.
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| 12. |
- Garpebring, Anders, et al.
(författare)
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Uncertainty estimation in dynamic contrast-enhanced MRI
- 2013
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Ingår i: Magnetic Resonance in Medicine. - : Wiley-Blackwell. - 0740-3194 .- 1522-2594. ; 69:4, s. 992-1002
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Tidskriftsartikel (refereegranskat)abstract
- Using dynamic contrast-enhanced MRI (DCE-MRI), it is possible to estimate pharmacokinetic (PK) parameters that convey information about physiological properties, e.g., in tumors. In DCE-MRI, errors propagate in a nontrivial way to the PK parameters. We propose a method based on multivariate linear error propagation to calculate uncertainty maps for the PK parameters. Uncertainties in the PK parameters were investigated for the modified Kety model. The method was evaluated with Monte Carlo simulations and exemplified with in vivo brain tumor data. PK parameter uncertainties due to noise in dynamic data were accurately estimated. Noise with standard deviation up to 15% in the baseline signal and the baseline T1 map gave estimated uncertainties in good agreement with the Monte Carlo simulations. Good agreement was also found for up to 15% errors in the arterial input function amplitude. The method was less accurate for errors in the bolus arrival time with disagreements of 23%, 32%, and 29% for Ktrans, ve, and vp, respectively, when the standard deviation of the bolus arrival time error was 5.3 s. In conclusion, the proposed method provides efficient means for calculation of uncertainty maps, and it was applicable to a wide range of sources of uncertainty.
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| 13. |
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| 14. |
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| 15. |
- Hilletofth, Per, et al.
(författare)
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Agent-Based Simulation Fusion for Improved Decision Making for Service Operations
- 2009
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Ingår i: Proceedings of the 12th International Conference on Information Fusion. - : IEEE. - 9780982443804
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Konferensbidrag (refereegranskat)abstract
- We use agent-based modeling and simulation to fuse data from multiple sources to estimate the state of some system properties. This implies that the real system of interest is modeled and simulated using agent principles. Using Monte-Carlo simulation, we estimate the values of some decision-relevant numerical properties, such as utilization of resources and service levels, as a decision support for a Maintenance Service Provider. Our initial results indicate that this kind of fusion of information sources can improve the understanding of the problem domain (e.g. to what degree some critical properties influence service operations) and also generate a basis for decision-making.
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| 16. |
- Hilletofth, Per, et al.
(författare)
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Agent-based simulation fusion for improved decision making for service operations
- 2009
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Ingår i: Proceedings of the 12th International Conference on Information Fusion. - Seattle, US. - 9780982443804 ; , s. 998-1005
-
Konferensbidrag (refereegranskat)abstract
- We use agent-based modeling and simulation to fuse data from multiple sources to estimate the state of some system properties. This implies that the real system of interest is modeled and simulated using agent principles. Using Monte-Carlo simulation, we estimate the values of some decision-relevant numerical properties. We use the estimated properties, such as utilization of resources and service levels, as a decision support for a Maintenance Service Provider. Our initial results indicate that this kind of fusion of information sources can improve the understanding of the problem domain (e.g. to what degree some critical properties influence service operations) and also generate a basis for decision-making.
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| 17. |
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| 18. |
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| 19. |
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| 20. |
- Jansson, Ronnie, et al.
(författare)
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Recombinant Spider Silk Genetically Functionalized with Affinity Domains
- 2014
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Ingår i: Biomacromolecules. - : American Chemical Society (ACS). - 1525-7797 .- 1526-4602. ; 15:5, s. 1696-1706
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Tidskriftsartikel (refereegranskat)abstract
- Functionalization of biocompatible materials for presentation of active protein domains is an area of growing interest. Herein, we describe a strategy for functionalization of recombinant spider silk via gene fusion to affinity domains of broad biotechnological use. Four affinity domains of different origin and structure; the IgG-binding domains Z and C2, the albumin-binding domain ABD, and the biotin-binding domain M4, were all successfully produced as soluble silk fusion proteins under nondenaturing purification conditions. Silk films and fibers produced from the fusion proteins were demonstrated to be chemically and thermally stable. Still, the bioactive domains are concluded to be folded and accessible, since their respective targets could be selectively captured from complex samples, including rabbit serum and human plasma. Interestingly, materials produced from mixtures of two different silk fusion proteins displayed combined binding properties, suggesting that tailor-made materials with desired stoichiometry and surface distributions of several binding domains can be produced. Further, use of the IgG binding ability as a general mean for presentation of desired biomolecules could be demonstrated for a human vascular endothelial growth factor (hVEGF) model system, via a first capture of anti-VEGF IgG to silk containing the Z-domain, followed by incubation with hVEGF. Taken together, this study demonstrates the potential of recombinant silk, genetically functionalized with affinity domains, for construction of biomaterials capable of presentation of almost any desired biomolecule.
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| 21. |
- Johansson, Andreas, et al.
(författare)
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Dynamic analysis of shuttle technique performance applied on hydraulic transformer
- 2002
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Ingår i: Proc. of the 3rd International Fluid Power Conference (IFK'3). - 9783826599002 ; , s. 249-261
-
Konferensbidrag (refereegranskat)abstract
- As an alternative to traditional valve coutrol, hydraulic transformation has proved to be an attactive approach from an efficiency point of view. According to the Innas1 concept, hydraulic transformation is achicved using a modified displacement machine design. In order to realise the transformation using only one displacement machine, it is necessary to use a valve plate containing three kidney slots for the three supply lines: supply, load and tank. By displacing the valve plate, pressure/flow ratio can be transformed, ideally with preserved efficiency. When using three kidney slots together with a traditional displacement machine with two dead centres, the commutation between two subsequent kidneys will occur while the piston is moving. This will result in pre-compression or decompression of the cylinder fiuid, with severe pressure peaks as a consequence. Besides noise and vibration, these pressure peaks will decrease the total efficiency considerably. Also driving shaft torque variations will appear, which will affect the rotational movement by speed fluctuations. In order to minimise the pressure peaks during valving land passages. small pistons between pairs of cylinders in the barrel are introduced. This is referred to as shuttle technique. Using these shuttles, excess of cylinder fluid during commutation can be transferred to adjacent cylinders, and thus prevent cylinder pressure peaks from appearing.It is very difficult to measure the internal states of the shuttle in an operating transformer. By using computer simulation techniques, detailed analyses of the internal workings of the shuttle can be performed. In this work, a detailed description of the dynamic behaviour of the shuttle is given. Advantages and disadvantages of the technique are discussed.1 Innas BV, Netherlands
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| 22. |
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| 23. |
- Johansson, L. Ronnie M., et al.
(författare)
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Bridging the gap between information need and information acquisition
- 2004
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Ingår i: Proceedings of the Seventh International Conference on Information Fusion, FUSION 2004. - Stockholm. - 917056115X ; , s. 1202-1209
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Konferensbidrag (refereegranskat)abstract
- In this article, we address the rarely discussed problem of connecting high-level information (e.g., aggregated states and enemy intentions) to information acquisition. Our approach is to partition the transition of information need to sensor management into a set of comprehensible entities (information types and functions), which we present in a framework. The framework is stepwise (sequential) and first translates actual information (from the data and information fusion process) to information need. The information need is mapped to the task space by a task management function which performs prioritization with respect to information need. A further step includes projection of tasks to service space by an allocation scheme, and finally services give orders to resources. In the terminology of the framework, we discuss the extension of a previous study (that involved plan recognition) with a sensor management function.
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| 24. |
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| 25. |
- Johansson, Ronnie, et al.
(författare)
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A Study on Class-Specifically Discounted Belief for Ensemble Classifiers
- 2008
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Ingår i: 2008 IEEE International Conference on Multisensor Fusion and Integration for Intelligent Systems. - : IEEE. - 9781424421442 - 9781424421435 ; , s. 614-619
-
Konferensbidrag (refereegranskat)abstract
- Ensemble classifiers are known to generally perform better than their constituent classifiers. Whereas a lot of work has been focusing on the generation of classifiers for ensembles, much less attention has been given to the fusion of individual classifier outputs. One approach to fuse the outputs is to apply Shafer’s theory of evidence, which provides a flexible framework for expressing and fusing beliefs. However, representing and fusing beliefs is non-trivial since it can be performed in a multitude of ways within the evidential framework. In a previous article, we compared different evidential combination rules for ensemble fusion. The study involved a single belief representation which involved discounting (i.e., weighting) the classifier outputs with classifier reliability. The classifier reliability was interpreted as the classifier’s estimated accuracy, i.e., the percentage of correctly classified examples. However, classifiers may have different performance for different classes and in this work we assign the reliability of a classifier output depending on the classspecific reliability of the classifier. Using 27 UCI datasets, we compare the two different ways of expressing beliefs and some evidential combination rules. The result of the study indicates that there is indeed an advantage of utilizing class-specific reliability compared to accuracy in an evidential framework for combining classifiers in the ensemble design considered.
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| 26. |
- Johansson, Ronnie, et al.
(författare)
-
Avskanning av dataanalys och AI – Rapport år 2023
- 2023
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Dataanalys och det närbesläktade området artificiell intelligens utvecklas snabbt och är av stort intresse för ledningsområdet då de kan erbjuda åtråvärda egenskaper som automatiserad hantering av stora datamängder och modeller för att tolka ny data. Den här rapporten omfattar en avskanning av fyra utvalda delområden: preskriptiv analys, osäkerhetshantering, förklarbarhet (XAI) och systemperspektiv. Rapporten innehåller dessutom en uppskattning av den framtida utvecklingen av delområdena och en jämförelse med avseende på deras mognadsgrad och relevans.
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| 27. |
- Johansson, Ronnie
(författare)
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Information Acquisition in Data Fusion Systems
- 2003
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- By purposefully utilising sensors, for instance by a datafusion system, the state of some system-relevant environmentmight be adequately assessed to support decision-making. Theever increasing access to sensors o.ers great opportunities,but alsoincurs grave challenges. As a result of managingmultiple sensors one can, e.g., expect to achieve a morecomprehensive, resolved, certain and more frequently updatedassessment of the environment than would be possible otherwise.Challenges include data association, treatment of con.ictinginformation and strategies for sensor coordination.We use the term information acquisition to denote the skillof a data fusion system to actively acquire information. Theaim of this thesis is to instructively situate that skill in ageneral context, explore and classify related research, andhighlight key issues and possible future work. It is our hopethat this thesis will facilitate communication, understandingand future e.orts for information acquisition.The previously mentioned trend towards utilisation of largesets of sensors makes us especially interested in large-scaleinformation acquisition, i.e., acquisition using many andpossibly spatially distributed and heterogeneous sensors.Information acquisition is a general concept that emerges inmany di.erent .elds of research. In this thesis, we surveyliterature from, e.g., agent theory, robotics and sensormanagement. We, furthermore, suggest a taxonomy of theliterature that highlights relevant aspects of informationacquisition.We describe a function, perception management (akin tosensor management), which realizes information acquisition inthe data fusion process and pertinent properties of itsexternal stimuli, sensing resources, and systemenvironment.An example of perception management is also presented. Thetask is that of managing a set of mobile sensors that jointlytrack some mobile targets. The game theoretic algorithmsuggested for distributing the targets among the sensors proveto be more robust to sensor failure than a measurement accuracyoptimal reference algorithm.Keywords:information acquisition, sensor management,resource management, information fusion, data fusion,perception management, game theory, target tracking
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| 28. |
- Johansson, Ronnie, et al.
(författare)
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Information Acquisition Strategies for Bayesian Network-based Decision Support
- 2010
-
Ingår i: FUSION 2010. - : IEEE conference proceedings. - 9780982443811 ; , s. 1-8
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Konferensbidrag (refereegranskat)abstract
- Determining how to utilize information acquisition resources optimally is a difficult task in the intelligence domain. Nevertheless, an intelligence analyst can expect little or no support for this from software tools today. In this paper, we describe a proof of concept implementation of a resource allocation mechanism for an intelligence analysis support system. The system uses a Bayesian network to structure intelligence requests, and the goal is to minimize the uncertainty of a variable of interest. A number of allocation strategies are discussed and evaluated through simulations.
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| 29. |
- Johansson, Ronnie, 1975-
(författare)
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Large-Scale Information Acquisition for Data and Information Fusion
- 2006
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The purpose of information acquisition for data and information fusion is to provide relevant and timely information. The acquired information is integrated (or fused) to estimate the state of some environment. The success of information acquisition can be measured in the quality of the environment state estimates generated by the data and information fusion process. In this thesis, we introduce and set out to characterise the concept of large-scale information acquisition. Our interest in this subject is justified both by the identified lack of research on a holistic view on data and information fusion, and the proliferation of networked sensors which promises to enable handy access to a multitude of information sources. We identify a number of properties that could be considered in the context of large-scale information acquisition. The sensors used could be large in number, heterogeneous, complex, and distributed. Also, algorithms for large-scale information acquisition may have to deal with decentralised control and multiple and varying objectives. In the literature, a process that realises information acquisition is frequently denoted sensor management. We, however, introduce the term perception management instead, which encourages an agent perspective on information acquisition. Apart from explictly inviting the wealth of agent theory research into the data and information fusion research, it also highlights that the resource usage of perception management is constrained by the overall control of a system that uses data and information fusion. To address the challenges posed by the concept of large-scale information acquisition, we present a framework which highlights some of its pertinent aspects. We have implemented some important parts of the framework. What becomes evident in our study is the innate complexity of information acquisition for data and information fusion, which suggests approximative solutions. We, furthermore, study one of the possibly most important properties of large-scale information acquisition, decentralised control, in more detail. We propose a recurrent negotiation protocol for (decentralised) multi-agent coordination. Our approach to the negotiations is from an axiomatic bargaining theory perspective; an economics discipline. We identify shortcomings of the most commonly applied bargaining solution and demonstrate in simulations a problem instance where it is inferior to an alternative solution. However, we can not conclude that one of the solutions dominates the other in general. They are both preferable in different situations. We have also implemented the recurrent negotiation protocol on a group of mobile robots. We note some subtle difficulties with transferring bargaining solutions from economics to our computational problem. For instance, the characterising axioms of solutions in bargaining theory are useful to qualitatively compare different solutions, but care has to be taken when translating the solution to algorithms in computer science as some properties might be undesirable, unimportant or risk being lost in the translation.
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| 30. |
- Johansson, Ronnie M., et al.
(författare)
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Particle filter-based information acquisition for robust plan recognition
- 2005
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Ingår i: 2005 7th International Conference on Information Fusion (FUSION), Vols 1 and 2. - 0780392868 ; , s. 183-190
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Konferensbidrag (refereegranskat)abstract
- Plan recognition generates high-level information of opponents' plans, typically a probability distribution over a set of plausible plans. Estimations of plans, are in our work, made at different decision-levels, both company-level and the subsumed platoon-level. Naturally, successful plan recognition is heavily dependent on the data that is supplied, and, hence, sensor management is a necessity. A key feature of the sensor management discussed here is that it is driven by the information need of the plan recognition process. In our research, we have presented a general framework for connecting information need to sensor management. In our framework implementation, an essential part is the prioritization of sensing tasks, which is necessary to efficiently utilize limited sensing resources. In our first implementation, the priorities were calculated from, for instance, the estimated threats of opponents (as a function of plan estimates), the distance to the opponent, and the uncertainty in its position. In this article, we add a particle filter method to more carefully represent the uncertainty in the opponent state estimate to make prioritization more well founded and, ultimately, to achieve robust plan recognition. By using the particle filter we can obtain more reliable state estimates (through the particle filter's ability to represent complex probability distributions) and also a statistically based threat variation (through Monte-Carlo simulation). The state transition model of the particle filter can also be used to predict future states to direct sensors with a time delay (a common property of large-scale sensing systems), such as sensors mounted on UAVs that have to travel some distance to make a measurement.
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| 31. |
- Johansson, Ronnie, et al.
(författare)
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On the Definition and Scope of Information Fusion as a Field of Research
- 2022
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Ingår i: ISIF Perspectives on Information Fusion. - : International Society of Information Fusion (ISIF). - 2831-4824 .- 2831-4832. ; 5:1, s. 3-12
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Tidskriftsartikel (refereegranskat)abstract
- A definition of information fusion (IF) as a field of research can benefit researchers within the field, who may use such a definition when motivating their own work and evaluating the contributions of others. Moreover, it can enable researchers and practitioners outside the field to more easily relate their own work to the field and more easily understand the scope of IF techniques and methods. Based on strengths and weaknesses of existing definitions, a definition is proposed that is argued to effectively fulfill the requirements that can be put on a definition of IF as a field of research. Although the proposed definition aims to be precise, it does not fully capture the richness and versatility of the IF field. To address that limitation, we highlight some topics to explore the scope of IF, covering the systems perspective of IF and its relation to ma-chine learning, optimization, robot behavior, opinion aggregation, and databases.
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| 32. |
- Johansson, Ronnie, et al.
(författare)
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Perception Management : An Emerging Concept for Information Fusion
- 2003
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Ingår i: Information Fusion. - : Elsevier. - 1566-2535. ; 4:3, s. 231-234
-
Tidskriftsartikel (refereegranskat)abstract
- The state-of-art of sensor management has been advanced to the extent where high-level information plays an increasingly important role. Recognizing the essential need of intelligent agents to perceive the environment to take appropriate actions, the article proposes the concept of perception management. It refers to controlling the process of data acquisition from the external world to enhance percepts obtained. The content of perception management is outlined and its relationship with sensor management is also discussed.
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| 33. |
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| 34. |
- Karlsson, Alexander, et al.
(författare)
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An Empirical Comparison of Bayesian and Credal Combination Operators
- 2010
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Ingår i: FUSION 2010. - : IEEE conference proceedings. - 9780982443811 ; , s. Article number 5711907-
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Konferensbidrag (refereegranskat)abstract
- We are interested in whether or not representing and maintaining imprecision is beneficial when combining evidences from multiple sources. We perform two experiments that contain different levels of risk and where we measure the performance of the Bayesian and credal combination operators by using a simple score function that measures the informativeness of a reported decision set. We show that the Bayesian combination operator performed on centroids of operand credal sets outperforms the credal combination operator when no risk is involved in the decision problem. We also show that if a risk component is present in the decision problem, a simple cautious decision policy for the Bayesian combination operator can be constructed that outperforms the corresponding credal decision policy.
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| 35. |
- Karlsson, Alexander, et al.
(författare)
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An Empirical Comparison of Bayesian and Credal Networks for Dependable High-Level Information Fusion
- 2008
-
Ingår i: Proceedings of the 11th International Conference on Information Fusion. - : IEEE. - 9783000248832 - 9783800730926 ; , s. 1359-1366
-
Konferensbidrag (refereegranskat)abstract
- Bayesian networks are often proposed as a method for high-level information fusion. However, a Bayesian network relies on strong assumptions about the underlying probabilities. In many cases it is not realistic to require such precise probability assessments. We show that there exists a significant set of problems where credal networks outperform Bayesian networks, thus enabling more dependable decision making for this type of problems. A credal network is a graphical probabilistic method that utilizes sets of probability distributions, e.g., interval probabilities, for representation of belief. Such a representation allows one to properly express epistemic uncertainty, i.e., uncertainty that can be reduced if more information becomes available. Since reducing uncertainty has been proposed as one of the main goals of information fusion, the ability to represent epistemic uncertainty becomes an important aspect in all fusion applications.
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| 36. |
- Karlsson, Alexander, et al.
(författare)
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An Empirical Comparison of Bayesian and Credal Set Theory for Discrete State Estimation
- 2010
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Ingår i: Information Processing and Management of Uncertainty in Knowledge-Based Systems. Theory and Methods. - Berlin, Heidelberg : Springer Berlin/Heidelberg. - 9783642140549 - 9783642140556 - 3642140548 ; , s. 80-89
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Konferensbidrag (refereegranskat)abstract
- We are interested in whether or not there exist any advantages of utilizing credal set theory for the discrete state estimation problem. We present an experiment where we compare in total six different methods, three based on Bayesian theory and three on credal set theory. The results show that Bayesian updating performed on centroids of operand credal sets significantly outperforms the other methods. We analyze the result based on degree of imprecision, position of extreme points, and second-order distributions.
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| 37. |
- Karlsson, Alexander, et al.
(författare)
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Characterization and Empirical Evaluation of Bayesian and Credal Combination Operators
- 2011
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Ingår i: Journal of Advances in Information Fusion. - : ISIF, International Society of Information Fusion. - 1557-6418. ; 6:2, s. 150-166
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Tidskriftsartikel (refereegranskat)abstract
- We address the problem of combining independent evidences from multiple sources by utilizing the Bayesian and credal combination operators. We present measures for degree of conflict and imprecision, which we use in order to characterize the behavior of the operators through a number of examples. We introduce discounting operators that can be used whenever information about the reliability of sources is available. The credal discounting operator discounts a credal set with respect to an interval of reliability weights, hence, we allow for expressing reliability of sources imprecisely. We prove that the credal discounting operator can be computed by using the extreme points of its operands. We also perform two experiments containing different levels of risk where we compare the performance of the Bayesian and credal combination operators by using a simple score function that measures the informativeness of a reported decision set. We show that the Bayesian combination operator performed on centroids of operand credal sets outperforms the credal combination operator when no risk is involved in the decision problem. We also show that if a risk component is present in the decision problem, a simple cautious decision policy for the Bayesian combination operator can be constructed that outperforms the corresponding credal decision policy.
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| 38. |
- Karlsson, Alexander
(författare)
-
Evaluating credal set theory as a belief framework in high-level information fusion for automated decision-making
- 2010
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- High-level information fusion is a research field in which methods for achieving an overall understanding of the current situation in an environment of interest are studied. The ultimate goal of these methods is to provide effective decision-support for human or automated decision-making. One of the main proposed ways of achieving this is to reduce the uncertainty, coupled with the decision, by utilizing multiple sources of information. Handling uncertainty in high-level information fusion is performed through a belief framework, and one of the most commonly used such frameworks is based on Bayesian theory. However, Bayesian theory has often been criticized for utilizing a representation of belief and evidence that does not sufficiently express some types of uncertainty. For this reason, a generalization of Bayesian theory has been proposed, denoted as credal set theory, which allows one to represent belief and evidence imprecisely. In this thesis, we explore whether credal set theory yields measurable advantages, compared to Bayesian theory, when used as a belief framework in high-level information fusion for automated decision-making, i.e., when decisions are made by some pre-determined algorithm. We characterize the Bayesian and credal operators for belief updating and evidence combination and perform three experiments where the Bayesian and credal frameworks are evaluated with respect to automated decision-making. The decision performance of the frameworks are measured by enforcing a single decision, and allowing a set of decisions, based on the frameworks’ belief and evidence structures. We construct anomaly detectors based on the frameworks and evaluate these detectors with respect to maritime surveillance. The main conclusion of the thesis is that although the credal framework uses considerably more expressive structures to represent belief and evidence, compared to the Bayesian framework, the performance of the credal framework can be significantly worse, on average, than that of the Bayesian framework, irrespective of the amount of imprecision.
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| 39. |
- Karlsson, Alexander, et al.
(författare)
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Imprecise Probability as an Approach to Improved Dependability in High-Level Information Fusion
- 2008
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Ingår i: Interval / Probabilistic Uncertainty and Non-Classical Logics. - Berlin, Heidelberg : Springer Berlin/Heidelberg. - 9783540776635 ; , s. 70-84
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The main goal of information fusion can be seen as improving human or automatic decision-making by exploiting diversities in information from multiple sources. High-level information fusion aims specifically at decision support regarding situations, often expressed as “achieving situation awareness”. A crucial issue for decision making based on such support is trust that can be defined as “accepted dependence”, where dependence or dependability is an overall term for many other concepts, e.g., reliability. This position paper reports on ongoing and planned research concerning imprecise probability as an approach to improved dependability in high-level information fusion. We elaborate on high-level information fusion from a generic perspective and a partial mapping from a taxonomy of dependability to high-level information fusion is presented. Three application domains: defense, manufacturing, and precision agriculture, where experiments are planned to be implemented are depicted. We conclude that high-level information fusion as an application-oriented research area, where precise probability (Bayesian theory) is commonly adopted, provides an excellent evaluation ground for imprecise probability.
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| 40. |
- Karlsson, Alexander, et al.
(författare)
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On the Behavior of the Robust Bayesian Combination Operator and the Significance of Discounting
- 2009
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Ingår i: ISIPTA ’09. - : Society for Imprecise Probability. ; , s. 259-268
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Konferensbidrag (refereegranskat)abstract
- We study the combination problem for credal sets via the robust Bayesian combination operator. We extend Walley's notion of degree of imprecision and introduce a measure for degree of conflict between two credal sets. Several examples are presented in order to explore the behavior of the robust Bayesian combination operator in terms of imprecision and conflict. We further propose a discounting operator that suppresses a source given an interval of reliability weights, and highlight the importance of using such weights whenever additional information about the reliability of a source is available.
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| 41. |
- Leon, Miguel
(författare)
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Enhancing Differential Evolution Algorithm for Solving Continuous Optimization Problems
- 2016
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Differential Evolution (DE) has become one of the most important metaheuristics during the recent years, obtaining attractive results in solving many engineering optimization problems. However, the performance of DE is not always strong when seeking optimal solutions. It has two major problems in real world applications. First, it can easily get stuck in a local optimum or fail to generate better solutions before the population has converged. Secondly, its performance is significantly influenced by the control parameters, which are problem dependent and which vary in different regions of space under exploration. It usually entails a time consuming trial-and-error procedure to set suitable parameters for DE in a specific problem, particularly for those practioners with limited knowledge and experience of using this technique. This thesis aims to develop new DE algorithms to address the two aforementioned problems. To mitigate the first problem, we studied the hybridization of DE with local search techniques to enhance the efficiency of search. The main idea is to apply a local search mechanism to the best individual in each generation of DE to exploit the most promising regions during the evolutionary processs so as to speed up the convergence or increase the chance to scape from local optima. Four local search strategies have been integrated and tested in the global DE framework, leading to variants of the memetic DE algorithms with different properties concerning diversification and intensification. For tackling the second problem, we propose a greedy adaptation method for dynamic adjustment of the control parameters in DE. It is implemented by conducting greedy search repeatedly during the run of DE to reach better parameter assignments in the neighborhood of a current candidate. The candidates are assessed by considering both, the success rate and also fitness improvement of trial solutions against the target ones. The incorporation of this greedy parameter adaptation method into standard DE has led to a new adaptive DE algorithm, referred to as Greedy Adaptive Differential Evolution (GADE). The methods proposed in this thesis have been tested in different benchmark problems and compared with the state of the art algorithms, obtaining competitive results. Furthermore, the proposed GADE algorithm has been applied in an industrial scenario achieving more accurate results than those obtained by a standard DE algorithm.
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| 42. |
- Lätt, Jimmy, et al.
(författare)
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In vivo visualization of displacement-distribution-derived parameters in q-space imaging.
- 2008
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Ingår i: Magnetic Resonance Imaging. - : Elsevier BV. - 1873-5894 .- 0730-725X. ; 26:1, s. 77-87
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Tidskriftsartikel (refereegranskat)abstract
- Objective This study aimed to explore the potential of in vivo q-space imaging in the differentiation between different cerebral water components. Materials and Methods Diffusion-weighted imaging was performed in six directions with 32 equally spaced q values and a maximum b value of 6600 s/mm2. The shape of the signal-attenuation curve and the displacement propagator were examined and compared with a normal distribution using the kurtosis parameter. Maps displaying kurtosis, fast and slow components of the apparent diffusion coefficients, fractional anisotropy and directional diffusion were calculated. The displacement propagator was further described by the full width at half and at tenth maximum and by the probability density of zero displacement P(0). Three healthy volunteers and three patients with previously diagnosed multiple sclerosis (MS) were examined. Results Simulations indicated that the kurtosis of a signal-attenuation curve can determine if more than one water component is present and that care must be taken to select an appropriate threshold. It was possible to distinguish MS plaques in both signal and diffusional kurtosis maps, and in one patient, plaques of different degree of demyelinization showed different behavior. Discussion Our results indicate that in vivo q-space analysis is a potential tool for the assessment of different cerebral water components, and it might extend the diagnostic interpretation of data from diffusion magnetic resonance imaging.
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| 43. |
- Lätt, Jimmy, et al.
(författare)
-
Regional values of diffusional kurtosis estimates in the healthy brain.
- 2013
-
Ingår i: Journal of Magnetic Resonance Imaging. - : Wiley. - 1522-2586 .- 1053-1807. ; 37:3, s. 610-618
-
Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: To provide estimates of the diffusional kurtosis in the healthy brain in anatomically defined areas and list these along previously reported values in pathologies. MATERIALS AND METHODS: Thirty-six volunteers (mean age = 33.1 years; range, 19-64 years) underwent diffusional kurtosis imaging. Mean kurtosis (MK), radial kurtosis (RK), mean diffusivity (MD), radial diffusivity (RD), and fractional anisotropy (FA) were determined in 26 anatomical structures. Parameter estimates were assessed regarding age dependence. RESULTS: MK varied from 1.38 in the splenium of the corpus callosum to 0.66 in the caudate head, MD varied from 0.68 to 0.62 μm(2) /ms and FA from 0.87 to 0.29. MK, and FA showed a strong positive correlation, RK and RD a strong negative correlation. Parameter estimates showed age correlation in some regions; also the average MK and RK for all WM and all GM areas, respectively, were negatively correlated with age. CONCLUSION: DKI parameter estimates MK and RK varied depending on the anatomical region and varied with age in pooled WM and GM data. MK estimates in the internal capsule, corpus callosum, and thalamus were consistent with previous studies. The range of values of MK and RK in healthy brain overlapped with that in pathologies. J. Magn. Reson. Imaging 2012. © 2012 Wiley Periodicals, Inc.
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| 44. |
- Mellin, Jonas, et al.
(författare)
-
Adaptive Application and Resource Management
- 2008
-
Ingår i: Proceedings of the second Skövde Workshop on Information fusion Topics (SWIFT 2008). - Skövde : University of Skövde. - 9789163336973 ; , s. 67-70
-
Konferensbidrag (refereegranskat)
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| 45. |
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| 46. |
- Müller, Christian, et al.
(författare)
-
Functionalisation of recombinant spider silk with conjugated polyelectrolytes
- 2011
-
Ingår i: Journal of Materials Chemistry. - : Royal Society of Chemistry. - 0959-9428 .- 1364-5501. ; 21:9, s. 2909-2915
-
Tidskriftsartikel (refereegranskat)abstract
- Conjugated polyelectrolytes are demonstrated to permit facile staining of recombinant spider silk fibres. We find that the polyelectrolyte concentration and pH of the staining solution as well as the incubation temperature strongly influence the efficiency of this self-assembly process, which appears to be principally mediated through favourable electrostatic interactions. Thus, depending on the choice of staining conditions as well as the polyelectrolyte, electrically conductive or photoluminescent recombinant silk fibres could be produced. In addition, staining of natural Bombyx mori silk is established, which emphasises the versatility of the here advanced approach to functionalise silk-based materials.
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| 47. |
- Mårtensson, Jan, et al.
(författare)
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Nurse-led heart failure follow-up in primary care in Sweden
- 2009
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Ingår i: EUROPEAN JOURNAL OF CARDIOVASCULAR NURSING. - : Oxford University Press (OUP). - 1474-5151 .- 1873-1953. ; 8:2, s. 119-124
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Tidskriftsartikel (refereegranskat)abstract
- Background: Little or no knowledge is available about which service is offered to patients with heart failure in primary care. Aims: To describe nurse-led follow-up of patients with heart failure in primary care in Sweden. Methods and results: A questionnaire was sent to all primary health care centres in Sweden and 6 10 of 939 centres returned the questionnaire. Special nurses had designated time for follow-up of heart failure patients at 18% (n = 111) of the centres, compared to 93% and 78% for diabetes and obstructive lung disease. Centres with nurse-led follow-up of heart failure patients more frequently provided heart failure information (pandlt;0.001), had more doctors interested in heart failure (pandlt;0.001), more often had special care programmes (Pandlt;0.001) and had more co-operation with the hospitals around patients with heart failure (pandlt;0.01), compared to centres without such follow-up (n = 499). Conclusion: In primary care in Sweden, nurse-led follow-up is uncommon for patients with heart failure, despite being common for patients with diabetes and obstructive pulmonary disease. To improve this situation in primary care, an increased number of specially trained nurses is needed, together with further research to ensure a high quality follow-up in primary care.
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| 48. |
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| 49. |
- Riveiro, Maria, 1978-, et al.
(författare)
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Modeling and analysis of energy data : state-of-the-art and practical results from an application scenario
- 2011
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- This paper presents a comprehensive summary of the state-of-the-art of energy efficiency research. The literature review carried out focuses on the application of data mining and data analysis techniques to energy consumption data, as well as descriptions of tools, applications and research prototypes to manage the consumption of energy. Moreover, preliminary results of the application of a clustering technique to energy consumption data illustrate the review.
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| 50. |
- Suzic, Robert, et al.
(författare)
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Realization of a bridge between high-level information need and sensor management using a common DBN
- 2004
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Ingår i: PROCEEDINGS OF THE 2004 IEEE INTERNATIONAL CONFERENCE ON INFORMATION REUSE AND INTEGRATION (IRI-2004). - NEW YORK : IEEE. ; , s. 606-611
-
Konferensbidrag (refereegranskat)abstract
- In a decision support system for military decision makers a plan recognition process provides estimates Of enemy plans. To respond to a changing and uncertain environment the plan recognition process requires timely and relevant information. We address the rarely discussed, yet crucial, issue of connecting the information needs of plan recognition to management of sensors. We have previously presented a framework for this purpose and here we give details of an implementation and provide some results. In our implementation both plan recognition, sensor management and the functions that connect them utilize the a priori knowledge stored in a Dynamic Bayesian Network.
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